question_answer 42)

  Can the instantaneous power output of an ac source ever be negative? Can the average power output be negative?

Answer:

                  In an RLC circuit, if applied e.m.f., then current developed, Instantaneous power output of the a.c. source It may be negative, because power might be absorbed at some instant. However, average power output over a cycle cannot be negative. It is usually positive or may be zero such as in LC circuit.